Supply and Demand (in that order)

Monday, February 12, 2018

One of the greatest labor force changes of the 20th century was the movement of workers out of farming. In 1900, more than two out of five workers were in agriculture. Now it is less than two workers out of every 100.

It's not that people stopped eating. Rather, farm machinery and innovation increased the amount of food that could be produced per farm worker by more than a factor of 10. Food got cheaper and that got people to buy more food, but not 10 times as much. The end result has been fewer jobs in agriculture.

Automation is expected to come to other industries and occupations, and it is tempting to forecast less employment for them too. A variety of studies are using engineering information to determine which jobs will be automated next.

While automation may be a question of engineering, job loss is even more a question of economics. A key part of the agriculture story is that people were unwilling to purchase all of the food that farmers were capable of producing, even though food was getting cheaper. But not all industries share this with agriculture.

Suppose that the automation in agriculture had only been for chicken farming and not for any other food production. Chicken would have gotten cheaper relative to beef, fish, vegetables, fruit, etc., and that would have caused people to buy more chicken and less of other types of food.

Many -- even most -- of the extra chickens produced would have been purchased by consumers, and there would have been less need to reduce employment in chicken farming.

The most dramatic job losses would have occurred in the food industries like beef and fish that were not automated and that compete with chicken. In other words, jobs that are difficult to automate from an engineering perspective may be exactly the jobs pushed to extinction by automation because they cannot compete.

It all depends on the competitive landscape and how willing are consumers, encouraged by lower prices, to absorb the extra output made possible by automation.

Trucking is a modern example, because engineers are predicting that machines will soon do a lot of the driving formerly done by trucking employees. But the result may be morejobs for people in trucking and fewer jobs for people in railroads, airlines and shipping that compete with trucking (unless they also get more productive at the same time that trucking does).

The result was an increase in the fraction of economists doing statistical work, because universities, businesses and government wanted more statistical analysis when computers made it became cheaper and more accurate. The fraction of economists doing theoretical work fell, precisely because their tasks were not automated.

So the more interesting economic question for a worker is not whether his job can be automated but whether he or she will miss out on automation to occur in the workplace of his or her primary competitors.

Wednesday, December 27, 2017

By cutting the statutory corporate tax rate and by permitting investment expenses to be immediately deducted from corporate income, the new tax law encourages corporations to enhance their workers' productivity by investing in structures, equipment and software.

The additional investment will accumulate over several years, which means that the full effect on productivity and wages will not be felt for several years.

The simplest model of investment and worker productivity agrees that aggregate wage increases would not be discernible in the first year following a permanent and unanticipated capital income tax cut because of the time that it takes for investment to be planned, executed and translated in to greater worker productivity.

But Krugman, Obama economic adviser Larry Summers, and I, among others, agree that our economy and this tax cut have some meaningful differences from the simple model. One of those differences is that President Trump's signature last week was not an entire surprise.

The U.S. had been behind most of the world in cutting its corporate rate, and it was largely a matter of time until the U.S. did the same, especially in 2016 when Republicans won the White House and both houses of Congress.

Throughout 2017, businesses were making plans understanding the very real possibility that federal corporate tax rates would be lower, and the execution of those plans are already adding a bit to worker productivity.

The simple model also ignores that a lot of businesses are not organized or taxed as U.S.-based C-corporations, which are the types of corporations that have been subject to high statutory rates by worldwide standards.

Reallocating activity to U.S.-based C-corporations can happen more quickly than the building of new structures or manufacturing new equipment does. This means that part of the productivity effect can occur quickly too.

The simple model also treats labor costs as variable, which is a reasonable treatment for multi-year time frames. But over a period of a few weeks or months, which is the time frame discussed by Professor Krugman, much of the labor costs are slow to adjust, due primarily to the fact that it takes time to attract and sign good employees.

With businesses anticipating productivity growth over the next several years, it makes sense for them to take some immediate steps to solidify their workforce. (It's odd that Krugman missed this effect: he frequently writes about the "JOLTS" labor data, the entire point of which is that labor costs adjust slowly from the perspective of weekly or monthly data).

I agree with Professor Krugman that actions speak louder than words in matters of economics. Although they sometimes agree, often businesses say one thing and do another. This is especially true when the federal government uses its regulatory might to encourage businesses to say the "right thing," as it did when it rolled out the Affordable Care Act a few years ago.

But it is inaccurate to claim that workers must wait before seeing any benefits of the corporate tax cut.

Monday, December 18, 2017

Since the 1990s, U.S. corporations have been subject to one of the highest statutory tax rates in the world. The high rate has caused them to rearrange their affairs to avoid investing, especially in lines of business subject to the full rate, and thereby reducing productivity and workers’ wages.

But now Republicans in Congress appear to have agreed on reducing the rate by 14 points, to 21 percent, plus the applicable state rate, bringing the total into line with the statutory rates elsewhere in the industrialized world.

President Trump had originally insisted on a federal corporate rate of no more than 20 percent, but Congress appears to have chosen 21 in order enhance the bill’s revenue outlook. It is worth assessing how much revenue was gained, and worker wages lost, by this deviation from the president’s plan.

Although I expect that the federal government will be getting less corporate tax revenue than it would without any tax reform, it is possible that the change from 20 to 21 percent by itself has little or no effect on revenue.

That one extra point may prevent the U.S. from undercutting a number of countries such as Spain, the Netherlands, Austria and Chile and thereby reduce the amount of business activity that relocates here from those nations.

So, as compared to the president’s plan, the IRS will be collecting an extra point on corporate income, but there will be less corporate income than there would have been.

The tax reform’s expensing provisions — generous deductions for new investment projects — also encourage business investment apart from the rate cut, and it has been argued that expensing provisions by themselves create a lot of the economic growth generated by the reform.

Thus, even if adding a point does little to enhance revenue, it may also do little to limit the wage gains that come with reforming corporate taxes.

It is important to remember that much business is not corporate business, but rather organized as partnerships, S-corporations, etc. Ideally these organizational decisions would be made for real business, rather than tax reasons.

It remains to be seen how the new corporate rate meshes with the reform of taxation of non-corporate businesses, because it depends on how the IRS and tax accountants interpret the new rules.

But I expect that there are some non-corporate businesses whose rates would have been a couple of points higher than a 20-percent corporate rate (plus the relevant personal income and state corporate taxation), so that adding a point to the corporate rate mitigates some of the unintended consequences on that margin.

Finally, future Congresses may be willing to further change the rates, especially to the degree that the changes are small. Recall that the last big corporate rate cut in 1986 was followed by a one-point change during the Clinton administration.

For all of these reasons, the consequences of a one-point deviation from the president’s plan are small compared to the overall economic benefits from a long-overdue reform of the corporate tax.

Monday, November 20, 2017

Taxes and regulations are known to affect the size distribution of businesses, due to the fact that smaller businesses are less subject to enforcement.Large informal sectors are an obvious result in developing countries, but measurement challenges have hindered quantifying the size distortions’ impact on developed-country employment and productivity.This paper uses new and unique data that is readily linked to a specific regulation: the 2010 Affordable Care Act’s (ACA) employer mandate.The mandate’s size provision took effect in 2015 and is especially interesting, not only due to its notoriety, but because of its bright-line threshold and enforcement by monetary penalty.This paper quantifies the size incentive of that penalty, develops a framework for combining evidence on size with evidence on voluntary compliance, and uses a new survey of businesses to quantify the number of businesses that changed from large to small as a consequence of the law.

The key size threshold in the ACA is 50 full-time equivalent employees (FTEs), which establishes the legal definition of a “large” business that is subject to the employer mandate.Momentarily ignoring the distinction between FTEs and total employment, I display in Figure 1 a time series of the share of employment by small businesses, by a 50-total-employees criterion, among private businesses sized 25-99.The data is sourced from the tables prepared by the Agency for Healthcare Research and Quality from the insurance/employer component of the Medical Expenditure Panel Survey. Both the 2015 and 2016 shares are well outside the range observed in the recent history 2008-14, and in the direction to be expected given that large employers were subject to a new regulation.

Garicano, Lelarge, and Van Reenen (2016) show how the distortionary effects of size-dependent regulations appear muted when the observer uses a different measure of size than regulators do.This is the case in Figure 1, which looks at total employment as opposed to the full-time equivalents specified by the ACA and has total employment binned rather broadly (25-49 and 50-99).Both Garicano, Lelarge, and Van Reenen (2016) and Gurio and Roys (2014) therefore obtain size measures that are especially close to regulator measures and find large size distortions in the French economy.They do not link the distortions to specific regulations, but instead focus on France where there are many size-dependent regulations thought to be binding.One of their estimation methods is to compare the actual firm size distribution to a Pareto distribution and measure the nonmonotonicity of the actual distribution in the neighborhood of the threshold.

The Mercatus-Mulligan data used in this paper has five measurement advantages.First, it separately measures full- and part-time employment and therefore can produce good proxies for FTEs.Second, the size distortion can be linked to a specific and relatively new regulation, which permits a before-after analysis as shown in Figure 1.Third, voluntary compliance – that is, offering employer-sponsored health insurance (ESI) even when exempt from the mandate – can be measured.This allows the measurement of size distortions to focus on businesses for which the employer mandate is binding.Fourth, the survey was not conducted at the corporate level and therefore did not require any corporation’s approval to publish results.Rather, individuals were confidentially surveyed, and these individuals happened to be managers at businesses.If the sample aggregate happens to reveal politically-incorrect business practices, such a finding cannot impugn any particular business.Fifth, the managers of the sample businesses were asked whether and how the law changed their hiring practices, with answers that can be compared to size and compliance.

Before-after comparisons between the Census Bureau business survey and the Mercatus-Mulligan survey show little change in the size distribution of businesses between 2012 and 2016, except among businesses in the total-employment range 40-74.Among the latter businesses, the employment percentage of those with less than fifty employees has increased from 37 to 45, and this does not count the fact that a number of 49ers reduce employment below 50 full-time-equivalent employees (FTEs) without reducing their total employment below 50.Annual time series from the MEPS-IC show an extraordinary jump in the employment percentage of those with less than fifty employees, beginning in 2015, which is the same year when the large-employer designation began its 50-FTE threshold.

The size distortion is closely linked with whether a business offers employer-sponsored health insurance (ESI) to its employees.Even by comparison with businesses employing fewer than 30 full-time workers, the propensity to offer ESI is low among employers with 30-49 full-time employees.The size of this dip in the ESI propensity indicates the prevalence of 49er businesses: they do not offer ESI and thereby keep employment low enough to avoid the ACA’s large-employer designation.The cross-section finding is my second and strongest piece of evidence that the ACA’s employer mandate is pushing a significant number of businesses below the 50-FTE threshold.

My point estimate is that the United States has 38,327 49er businesses that collectively employ 1.7 million people.This translates to roughly 250,000 positions that are absent from 49er businesses because of the ACA, but the Mercatus-Mulligan sample by itself is not well suited for accurately assessing the average number of positions that the 38,327 49er businesses eliminated.The sample also indicates that businesses continue to adjust their employment over time.For example, many of them reported that, because of the ACA, they hire fewer workers or at least fewer full-time workers, but tried not to adjust the situations of their existing employees.If the ACA and its employer mandate remains in place, perhaps the prevalence of 49er businesses will increase over time.

By definition, the 49er businesses have less than 50 FTEs and do not offer ESI.But it appears that a majority of them had been offering it in the prior year.Employers with 30-49 FTEs are also disproportionately likely to report that they hire less or have shorter work schedules because of the ACA.This is my third finding pointing toward an economically significant effect of the ACA on the size distribution of businesses.To my knowledge, this is the first paper to find a business-size distortion that is readily visible in aggregate U.S. data.It is also remarkable that the distortion can be linked to a specific regulation with a precisely known penalty for violations.

Individual-based surveys of businesses are rarely used in economics, but that is bound to change as the survey industry is becoming more efficient (i.e., cheaper for the researcher).It is worth noting the contrast between the Mercatus-Mulligan survey design and in-depth studies of a particular business (e.g., (Einav, Knoepfle, Levin, & Sundaresan, 2014; Handel & Kolstad, 2015)).The former design has the advantage of representing a wide range of industries and geographic areas.Moreover, this study is not sponsored by any business and therefore does not require a corporation’s approval for its release.Corporate approval is a concern for studies of a particular business, especially when the topic involves public-relations-sensitive issues such as distorting business practices to lessen the cost of well-intended federal regulations.Another dividend from using a professional survey research firm is that every respondent completed the survey.

This paper does not put its estimates into an equilibrium framework. Future research needs to estimate the number of eliminated positions at 49er businesses that resulted in jobs created at businesses that compete with 49ers in product or labor markets.To the extent that the employer mandate shifts employment from 49ers to other businesses, future research needs to assess the aggregate productivity loss from the shifts, recognizing that the ACA’s large-employer definition is just a vivid example of a more general pre-existing enforcement phenomenon.Even without the ACA, businesses are taxed and regulated, and understand that adding to their payroll tends to increase the enforcement of those rules, albeit not discretely at 50 FTEs (Bigio & Zilberman, 2011; Bachas & Jensen, 2017).One ingredient in such productivity calculations would be the number of positions shifted, which I found to be roughly 250,000.

From the equilibrium perspective, another interpretation of my cross-section finding – the nonmonotonic relationship between ESI and employer size around the threshold – is that businesses below the threshold did not adjust their size but merely dropped their coverage, in which case, I have mislabeled them as 49ers.Indeed, I find that such businesses are disproportionately likely to have dropped their coverage in the past year.However, this alternative explanation does not by itself explain why (i) so many businesses were added to the 25-49 (total employment) size category, (ii) so few were added 50-99, or (iii) coverage rates are not particularly low for businesses with less than 30 FTEs.

The implementation of the employer penalty in January 2015 coincides with a sudden slowdown in the post-recession recovery in aggregate work hours per capita, with 2016 national employment about 800,000 below the trend prior to the implementation of the employer penalty (Mulligan, 2016). This paper’s estimates permit us to gauge the aggregate importance of the 49er phenomenon, not counting the marginal employment impact on non-ESI businesses that continue to employ 50 or more FTEs. If 250,000 positions were the aggregate employment effect of 49ers (see the equilibrium caveat above), that would be about one third of the recovery slowdown. Perhaps more important would be the social value of those positions, given that employment and income are substantially taxed by payroll, income, and sales taxes even without the ACA thereby creating a wedge between the positions’ social and private values. If that wedge were $20,000 annually, that would be $5 billion of lost annual social value, plus the usual Harberger triangle, which is 38,327 businesses in the quantity dimension and up to $68,987 annually in the price dimension (about $1 billion annually).

Monday, November 13, 2017

President Trump says that U.S. corporations face the highest tax rates in the world, whereas opponents of his tax reform say that “actual” corporate tax rates are in line with other countries. What gives?

The president is referring to the rate that applies to taxable corporate income, known as the “statutory rate.” The federal statutory rate is 35 percent, and the combined federal-state corporate rate is typically about 39 percent. This rate is greater than anywhere in the industrialized world.

But the statutory rate does not apply to all of the income-generating activities of corporations, because some of those activities create deductions that can be subtracted from business income for corporate-tax purposes.

Debt-financed activities are a good example, because the income they generate goes corporate-tax free to the extent that it can be distributed to investors as interest income.

Intellectual property investments are another example, because they are not obviously attached to a physical location, thereby helping accountants assign their returns to Ireland and other low-tax jurisdictions.

As a result, corporations are paying less than 39 percent of their income to state and local treasuries. The Government Accountability Office estimates 17 percent, which it calls the “effective rate.”

It might seem that the 22-percentage-point difference results in a free lunch for corporations at the government’s expense. But the opponents of corporate tax reform are mistaken to ignore the fact that the corporate tax has corporations paying a lot more than the checks they write to government treasuries.

The Internal Revenue Service (under the Obama administration) estimated that corporations and partnerships pay over $100 billion annually in complying with business-tax laws, including their costs of recording, keeping and hiring paid tax professionals. Compliance costs are not checks written to the government, but are real costs nonetheless.

In fact, the high compliance costs are a symptom of the low effective rate because business-tax deductions are a complicated enterprise. Corporations are paying for some of their 22-point savings in terms of the extra compliance costs that come with complicated tax strategies.

More important, our economy is less productive because taxes have induced investors to pursue tax-favored activities beyond what value creation would dictate. The most vivid example is the housing sector, where returns have been depressed by a factor of two or three because those returns are essentially tax free.

In other words, by having so many deductions, the corporate tax involves a substantial hidden tax on businesses beyond what they pay the government, with the extra payment in terms of lost income.

The chart below illustrates by splitting the economy into two kinds of activities: those that pay full tax and those that are tax favored.

If nobody adjusted their investment plans, the tax-favored activities would be a great deal — they would earn the amount up to the dashed line and owe no tax. But there is no free lunch. The tax favors induce investors to engage more in those activities.

Their movement depresses the income accruing there — otherwise nobody would be willing to do the activities subject to full tax. The chart illustrates this by showing how the income ultimately earned has been depressed enough so that the net-of-tax earnings is the same for both types of activities.

The low effective corporate tax rate is therefore not an argument against President Trump’s call for tax reform. That low rate is further evidence of the economic damage done by the tax, as businesses pay to comply and pay by accepting comparatively low-return investments.

Because the effective rate only counts costs in the form of payments to government, a low effective rate is telling us that cutting the corporate tax will benefit economic performance far more than it will cost government treasuries.

Sunday, November 5, 2017

To acknowledge the 100th anniversary of the Russian revolution, I have assembled data -- from Holmes (2009), Pipes (2001), Fontova (2013), and others -- on Communist regimes that lasted more than 5 years.

[Communists] openly declare that their ends can be attained only by the forcible overthrow of all existing social conditions. Let the ruling classes tremble at a Communistic revolution. The proletarians have nothing to lose but their chains. They have a world to win. Working men of all countries, unite!

(1) The chart below counts Communist state killings -- war deaths not included -- of its own people by purge, massacre, concentration camp, forced migration, famine, or escape attempt.

The counts are expressed as a percentage of population. 6% is a typical result.

You might say, "94% of people survive Communist regimes." But that's a lot less than the percentage of people who survived history's major tragedies. The U.S. Civil War was especially deadly, but "only" killed 2% of the population and, unlike the 6% above, this counts war deaths (civilian deaths were more like 0.2%). AIDS/HIV killed "only" 2% of Africa's population.

(2) Facts about Communist results are not part of the standard training in economics. Indeed, as recently as 1989, they were denied by some of our best and brightest. E.g., Samuelson and Nordhaus' best-selling textbook asserted "the Soviet economy is proof that, contrary to what many skeptics had earlier believed, a socialist command economy can function and even thrive."

(3) Another example: this year's New York Times commemorated the Russian revolution with fantastic claims such as "Women had better sex under socialism." That article shows a photo of a smiling woman on "a collective farm near Moscow" without mentioning how the Communist system left women and men so malnourished that their bodies no longer functioned normally. Take a look at the birth rate in Ukraine under Stalin:

(4) The above are examples of the intellectual class indulging their fantasies about the effects of apparently well-intentioned public policies. But the more general phenomenon was that results were suppressed, both outside and inside the Communist countries, because they were unpleasing to those in power.

(5) Disastrous results can more easily become public when there is competition both in the media and in the public sector. Obviously the Communist regimes operate in a one-party system. But even in our political system, the competition is far from perfect, and both media and state officials sometimes work together to attract attention away from negative results.

It is not so easy to have a government that tightly controls economic resources, but is unable and unwilling to exercise control over ideas.

Perhaps even Senator Bernie Sanders, who has admired more than one Communist regime and insists that government should freely provide everything from health care to college to housing, might now notice as much: his presidential campaign was one of the most recent victims of the Party Line and political collusion.

“labor market outcomes in the aggregate were not significantly affected.”

Theirs is a working paper and I'm sure that the authors are eager to add data and analysis, so I understand the above conclusions to have been modestly offered. With that said, it is worth recognizing that the above conclusions are not what the working paper shows.

Table 4 (the paper's first table on labor market outcomes) shows that the ACA reduced nationwide labor force participation by 349,190 in 2016, plus however much the ACA reduced labor force participation in a geographic area that was fully insured before the ACA, which I call the HFIA (Hypothetically Fully Insured Area). This effect is economically significant and, when combined with items (2) and (3) below, is easily in line with "the negative effect on jobs that the law's critics claimed it would be."

[Admittedly, the 349,190 is probably not statistically significant by the usual criteria, but the quotes above are not claiming that either side could be correct. Rather they claim to decisively reject "critics" who made claims right in line with the Duggan-Goda-Jackson point estimate. See below for the derivation of the 349,190]

The paper assumes, without much explanation, that the HFIA part of the ACA's impact is zero. But other work has shown that near-elderly insured people were given a tremendous incentive to retire early. In other words, basic economics tells us that the HFIA part is likely positive (i.e., in the same direction as the 349,190) and we should not assume it to be close to zero until we have further measurement.

The empirical methods in the paper, which emphasize differences among geographic areas such as Medicaid expansion states versus other states, are not designed to detect effects of the employer penalty. The employer penalty is the same amount throughout the nation. The penalty creates large labor-market distortions; those distortions that have been measured in other studies have proven to be similar across geographic areas. Moreover, the employer penalty did not apply until the 2016 coverage year, whereas 8/9 of the working paper's data is before that date. This is an especially serious problem for the low-income population, where the employer penalty in effect has them working 50-60 days per year for the government, on top of the implicit and explicit employment/income taxes they would pay even without the ACA (this fact is nowhere mentioned in the paper). For this reason, the authors' claim than that "lower income individuals were actually incentivized to work more" is especially incredible.

To derive the 349,190, look at the first "Out of the labor force" column of that table. The first row says that the M variable reduces out of the force by 0.0847 on average for each working-age person in the U.S. The second row says that the E variable increases out of the labor force by 0.0962. The mean of the M and E variables are, respectively, 0.073 and 0.086 (p. 11 of the paper). So, relative to the HFIA, their regression says that the U.S. has increased out of the labor force by 0.0021 per working-age person:

0.0021 = 0.073*(-0.0847) + 0.086*(.0962)

To get a number of people, multiply by the number of working age people (difference between thesetwo), and you get 349,190.

Tuesday, October 24, 2017

Delong and Krugman are now claiming that the Furman ratio -- defined by Furman himself to be the ratio of wage gains from a corporate-income tax cut to a "static" revenue loss defined as rate change times corporate income -- is equal to one, rather than being greater than one (namely, equal to 1/(1-t)) as Greg Mankiw showed.

They go on to claim that Mankiw made this supposed mistake as a political ploy.

But it is they who are making a mistake, in "Dem's favor" (purely accidental, I'm sure).

Specifically, Krugman says that his blue rectangle is the wage gain from a small tax cut. I agree. But it is wrong to equate that to Furman's static revenue loss, because that loss is strictly smaller than his rectangle. As Jason Furman confirms, Delong makes the same mistake algebraically by equating Furman's static revenue loss to his term "(a)" plus term "(b)" when in fact the loss is just his term "(a)".

Krugman's blue rectangle, and DeLong's (a)+(b), cannot be Furman's static revenue loss, because they incorporate an equilibrium price change in the calculation of the corporate-income tax base. The static revenue loss from the corporate-income tax must, by Furman's definition of "static," hold corporate income constant.

[Unlike DeLong, Krugman does not actually use the word "static." He says "direct" -- it is possible that he understands Furman's static and Krugman's direct to be different, and just failed to indicate the distinction to his readers.

It's fine if he prefers his blue rectangle to Furman's "static" revenue loss, but remember that by all accounts the blue rectangle is about $400b/year -- close to CEA's estimate of the wage gain.

In other words, when you change to the blue-rectangle definition of "static" you not only reduce the theoretical Furman ratio by a factor of (1-t), you also increase the static revenue number by the same factor. The CEA's $4k per family is fixed.

This is like measuring things in yards or meters or fathoms -- the standard you choose does not change the answer, as long as you are consistent about the standard ... let's watch to see if they are.]

Later Krugman talks about yet another concept of revenue loss, namely the actual (a.k.a., dynamic) loss. Mankiw had already explained the static-dynamic distinction to his readers. This morning I tried to help Mr. Krugman with this by posting on his twitter:

What @delong is seeing is that "static" revenue loss is arbitrary:

the static revenue loss from a per-unit tax cut [what Krugman shows with his blue rectangle and calls "direct"]

is different from [Furman's] static loss from an ad valorem tax cut [what a corporate-income tax cut would be],

even when those cuts are scaled so that both have the same effects on revenue and the surplus of all parties.

That is why I use actual revenue loss.

The ratio between the two "static" concepts is the (1-t) factor that has Delong and Krugman so confused.

Sunday, October 22, 2017

Contrary to Summer's claim, this result is not "unprecedented in analyses of tax incidence" rather it is one of the most ubiquitous results in analyses of tax incidence.

Notice that Summers' response this morning fails to claim that I am wrong about the LONG-RUN incidence in HIS MODEL (It should already be obvious that I am not wrong -- my early post already provided the algebraic analysis of, and precise citation to, the relevant equation from his paper).

Perhaps Summers really means that he thinks that the long-run incidence in HIS MODEL can be safely ignored. If that's what he means, he should say it directly and then I will respond.

Summers also either (i) fails to read what I wrote, or (ii) is lying. A cue: he fails to directly quote me. Specifically,

He claims that "Mulligan also fails to recognize that a corporate rate cut benefits capital and hurts labor outside the corporate sector because it draws capital out of the noncorporate sector, raising its marginal productivity and reducing that of labor." [emphasis added] But of course I did -- it is my item (C) -- and pointed readers to one of Summers supply-side-economics papers on that very subject.

He claims that Greg and I overestimate the effect of Trump's plan on the incentive to invest (see his "a cut in the corporate tax rate from 35 to 20 percent in the presence of expensing of substantial or total investment has very little impact on the incentive to invest"). But Greg and I are looking at INFINITESIMAL changes -- it doesn't get any smaller than that!

(For your reference, my item (C) says "...labor likely benefits from corporate income tax cuts even without any increase in the aggregate capital stock because that capital would be better allocated to the corporate sector." [emphasis added])

(Update: The Wall Street Journal referred to "a 1981 paper" where Summers wrote about "the increase in gross wages which results from the increased capital intensity arising from eliminating capital taxation." That's a different paper, published in the American Economic Review. As shown from my link, I am referring to the Summers paper published in the 1981 Brooking papers)

Furman and now Krugman (update: and now Summers) are admitting that simple supply and demand vividly contradicts what they said/say about taxes, but assert that the world is more complicated. I agree.

But they are dead wrong to further assert, without evidence (and I suspect without thinking), that adding complications will overturn the simple supply and demand conclusion or at least weaken the contradiction contained in their original proclamations.

(So far, Summers has wisely refrained from trying to defend his mistake. Update: he replied 2 hours after I posted this -- see the update at the very end of this post.)

can give quantitative answers. Greg Mankiw writes "I must confess that I am amazed at how simply this [quantitative formula] turns out. In particular, I do not have much intuition for why, for example, the answer does not depend on the production function." Supply and demand can answer his question, without any algebra.

can deal with complexities, such as "imperfect competition." The simple supply and demand model assumes perfect competition, but that assumption can be and has been modified. Guess what?! Making that modification shows that even the simply supply and demand model, let alone the proclamations of Furman-Summers-Krugman, understates the wage impact of capital-income taxation.
[Hints: what new rectangles appear when the factor-renter is selling his product for more than marginal cost? What determines the equilibrium size of those rectangles? Why should we use the corporate tax to rather than the DOJ to fight monopoly?]

can deal with complexities, such as debt finance. Having uneven taxation of different types of capital tends to reduce the denominator of the Furman ratio more than it reduces the numerator. i.e., Furman still has it even more backwards than I thought (update: Summers too).

explains why horizontal capital supply is not an "extreme" case. Gary Becker and I explained why capital supply probably slopes down somewhat in the long run (thanks Kevin M. Murphy for reminding me about this -- not to mention for teaching so many of us about price theory!)

shows you how to process the economic data. Furman and Krugman make evidence-free proclamations about the elasticity of capital supply. Supply and demand shows what economic data is needed to measure that elasticity (spoiler: it's not complicated, and shows a very high elasticity).

Supply and Demand (in that order)

The basic tools of supply and demand help immensely to understand and predict everyday events in our world. These days, many of those events are related to the Redistribution Recession of 2008-9. But I also look at other issues related to fiscal policy, labor economics, and industrial organization.